http://www.englishforums.com/search/pro.htm?q=user%3aJules&o=DateDescendingSearch results for 'user:Jules'en-USXMOD (Build: 3615.29165)http://www.englishforums.com/English/UsageCommaGuestTharabg/cqc/post.htm#974Wed, 18 Jun 2003 12:30:03 GMT946f00bb-57d3-4b7b-a9a2-059b5341af52:974julesIf I want a sentence clear of any doubt then it has to be number 1 in your examples. In your examples you have cleverly chosen items that are linked, e.g. Tape and Disk Drives, along with other references around the same topic. In your second example we see no seperation between "Tape, Disk Drive, and Consoles. Are they all related? If it is highly important to provide seperation between items, example 1 is the only way you can do this, hence why it is the best format to use.http://www.englishforums.com/English/UsageCommaGuestTharabg/cqc/post.htm#920Tue, 17 Jun 2003 12:16:07 GMT946f00bb-57d3-4b7b-a9a2-059b5341af52:920julesI would always use a COMMA before AND unless the last 2 items are related. For example, 1, 2, 3 and 4, would suggest 3 and 4 are coupled. 1, 2, 3, and 4 provides an absolute definition suggesting that the 3 and the 4 are seperate entities, which they are!